Saratoga Harness Track Horses Quarantined for EHV-1
Five horses in Barn 29 at Saratoga Harness Track, in Saratoga Springs, New York, have shown signs of equine herpesvirus-1 (EHV-1), including fever, mild coughing, and mild nasal discharge. On Jan. 28, New York State Department of Agriculture and Markets (NYSDAM) and New York State Gaming Commission (NYSGC) officials received laboratory test results on one of the horses, which indicated an active EHV-1 infection. None of the horses are exhibiting neurologic clinical signs.

Officials quarantined Barn 29 on Jan. 29 and will monitor for fever and other signs of illness for 21 days after the last signs of EHV-1 infection. Quarantined horses will not be allowed to leave the facility during that period. Exposed horses in Barn 29 that are well enough to train may do so when all other horses have left the track area at the end of each day.

EHV 101

Herpesvirus is highly contagious among horses and can cause a variety of ailments in equids, including rhinopneumonitis (a respiratory disease usually found in young horses), abortion in broodmares, and equine herpesvirus myeloencephalitis (EHM, the neurologic form).

In many horses, the first or only sign of EHV-1 infection is fever, which can go undetected. In addition to fever, other common signs of EHV-1 infection in young horses include cough, decreased appetite, depression, and a nasal discharge. Pregnant mares typically show no signs of infection before they abort, and abortions usually occur late in gestation (around eight months) but can be earlier. Abortions can occur anywhere from two weeks to several months following infection with EHV-1.

Horses with EHM usually have a fever at the onset of the disease and might show signs of a respiratory infection. A few days later, neurologic signs such as ataxia (incoordination), weakness or paralysis of the fore- and hind limbs, urine retention and dribbling, loss of tail tone, and recumbency (inability to rise) develop.

Herpesvirus is easily spread by nose-to-nose or close contact with an infectious horse; sharing contaminated equipment including bits, buckets, and towels; or clothing, hands, or equipment of people who have recently had contact with an infectious horse. Routine biosecurity measures, including hygiene and basic cleaning and disinfection practices, should be in place at all times to help prevent disease spread.

Current EHV-1 vaccines might reduce viral shedding but are not protective against the neurologic form of the disease. Implementing routine biosecurity practices is the best way to minimize viral spread, and the best method of disease control is disease prevention.